Psychology ETDs

Publication Date

6-26-2015

Abstract

It is well established that heavy ethanol exposure during prenatal brain development leads to drastic morphological, cognitive and behavioral consequences. In contrast to heavy exposure, the effects of moderate prenatal alcohol exposure (PAE) are less severe yet continue well into adulthood. Animal models of PAE have been of immense importance to researchers for their ability to control for extraneous variables such as socio economic status, age, nutrition, stress, and co-exposure to other substances. Studies of moderate PAE have investigated several discrete brain regions, neurotransmitter systems, and animal behaviors. However, the effects of moderate PAE on resting state functional network connectivity (FNC) have not been well characterized. Moreover, the relationship between PAE, functional connectivity, and animal behavior has not been previously investigated. The present study determined whether moderate PAE alters whole brain FNC. Furthermore, the relationship between hippocampal FNC and behavior was investigated. Long-Evans rats were exposed to 5% ethanol or saccharin throughout the entire gestational period. In adulthood, rats were anesthetized (1.0-2.3% isoflurane) and BOLD signals were acquired during a 10 min echoplanar imaging sequence in a 4.7T Bruker Biospin scanner. Following motion correction, spatial normalization and smoothing, spatial group independent component analysis (gICA) was performed using the Infomax algorithm implemented in the GIFT toolbox. A total of 17 non-artifactual components were retained for analysis of spectral power and connectivity. Components were observed in cortical, hippocampal, striatal, thalamic, and cerebellar structures. Cortical, hippocampal, and midbrain regions frequently stood out as areas that displayed more significant prenatal treatment differences. PAE animals displayed reductions in low frequency spectral power for several components. PAE animals often displayed a loss of strength in connectivity. Furthermore, analyses of social behaviors with hippocampal related connectivity showed that cortex-to-hippocampus (Cx-H) connectivity is most sensitive to alcohol exposure. PAE females and males displayed more negative correlations compared to their respective saccharin comparison groups. The results indicated that moderate fetal ethanol exposure can have long-lasting consequences on functional connectivity and that hippocampal-containing connectivity was linked to alterations in social behavior.

Degree Name

Psychology

Level of Degree

Masters

Department Name

Psychology

First Committee Member (Chair)

Savage, Daniel

Second Committee Member

Calhoun, Vince

Sponsors

National Institutes of Health COBRE grant P30GM103400,and the National Institute on Alcohol Abuse and Alcoholism grant 019462 and supplement grant 13-0447.

Language

English

Keywords

Fetal Alcohol Spectrum Disorders, Functional Connectivity, Social Behavior

Document Type

Thesis

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